The most common way to lock and unlock an access-controlling object such as a door is probably by using a mechanical key. This solution is cost efficient and easy to use, and a mechanical lock is hard to force. The drawbacks are, however, that the user always has to bring the key and that a user having a key always can obtain access, since the key itself does not incorporate any restrictions. These and other problems have been addressed by the present applicant in the previous application WO-2006/098690, which describes a device and method for unlocking a lock by a lock device enabled for short-range wireless data communication in compliance with a communication standard.
The device and method described in WO-2006/098690 presents a solution to the above problems. The present invention mainly relates to improvements in the lock device and its actuation, while the method related to communication between the lock device and external units may be similar to what has already been described in said previous application.
Desired features for the lock device is operational safety and low power consumption, and it is beneficial if this can be achieved with a device having a limited physical size. Though the device presented in the previous application was, and still is, advantageous there are improvements to be made within the above desired features.
A common feature for lock devices of the above type is that there is generally no simple way of determining the position of the lock catch. The angular position of a lock knob on the inside of the door is usually not reliable, since a lock catch also can be actuated by using a key from the outside. If the lock catch is locked/released with a key from the outside, this will generally not affect the angular position of the lock knob.
The solutions provided for in prior art for detecting the position of the lock catch in order to determine when the door is locked/unlocked, generally includes the provision of specific sensors in the actual lock mechanism or on another structural component of a lock, which makes these alternatives more costly and complex, both in terms of components needed and in terms of installation efforts. They are also disadvantageous in terms of power consumption.
The inventive concept can be used on any existing lock having rotatable lock actuating means on the inside, and can with ease be installed on most commercial locks using a lock knob. The inventive concept is also applicable when producing locks, and can as such be incorporated into lock cases during production thereof.